[R-sig-eco] Distance matrix based on correlation coefficient

[Gavin Simpson]

On Tue, 2010-07-20 at 23:35 +0300, Jari Oksanen wrote:
> On 20/07/10 22:42 PM, "Gavin Simpson" <gavin.simpson at ucl.ac.uk> wrote:
> 
> > On Tue, 2010-07-20 at 12:12 -0700, Dragos Zaharescu wrote:
> >> I would much appreciate if someone would enlighten me on how to calculate a
> >> distance matrix based on correlation coefficient (Spearman)? The simple
> >> correlation matrix seems not to work.
> > 
> 
> >> 1 - cor(dat) ## dissimilarity
> >
> Actually the canonical transformation to distance is sqrt(2-2*cor(dat)).
> 
> Cheers, Jari Oksanen

Of course, thanks Jari. That 1 - bit was total rubbish, not even
acknowledging that cor could be negative. Not sure what came over me; I
blame the heat here in London ;-)

Hangs head in shame.

G

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